It's about control. The CCP sees religion as a threat because it challenges the party's atheistic view. The underlying issue is the rejection of a pluralistic society which religion is a part of it as well as language, way of life, etc...
Don't get me wrong, of course I knew it's about regional control. But even the wiki entry acknowledges that religious freedom is different in different regions of China. Other regions don't have any restriction at all. Hence my point that accusing China for religious repression is missing the point. It doesn't justify its actions but the issues are more deeply geopolitical.